NEW YORK (Reuters) - Petra Kvitova’s hand might not yet be back to full strength but it is getting close to the level she had reached before an assault threatened her career as she prepares to face Garbine Muguruza in the fourth round of the U.S. Open on Sunday.

The Czech, a double Wimbledon champion, was sidelined for five months after suffering a serious injury on her left hand when stabbed at her home and she made her return to competition at the French Open in May.

She has made steady progress since then and her confidence is growing.

“I‘m still working on the strength, I think, which is still missing,” she said. “I do feel much more better and closer to my top level.”

Even if she holds a 2-1 career record against the pre-tournament favourite Muguruza, that might not be enough for the 13th seed to beat the two-time grand slam champion Spaniard, who has only dropped nine games in her first three matches in New York.

Muguruza won the title in Cincinnati before the U.S. Open and is on an eight-match winning streak.